Granulocyte-macrophage colony stimulating factor (GM-CSF) is a very important agent for the treatment of neutropenia induced by chemotherapy and AIDS and for the treatment of hematopoietic diseases e.g. aplastic anemia. GM-CSF may also play a role in stimulating the growth of hematopoietic tumors e.g. juvenile chronic myelogenous leukemia. Although this agent is important for the treatment of human disease and possibly plays a causative role in the growth of some neoplasms, little is known about the biochemical mechanism of action of this agent. It is goal of this project to understand how GM-CSF binding to its receptor leads to the induction of genes associated with cell growth and differentiation. Preliminary results from our laboratory have demonstrated important facts about the GM-CSF receptor, the mechanism of signal transduction by GM-CSF, and the genes activated soon after GM-CSF binds to its receptor. We find that two mRNAs encode the alpha subunit of GM-CSF receptor. One of these has a single peptide but no transmembrane domain suggesting that it is secreted. We find that binding of GM-CSF to its receptor activities both tyrosine kinases and protein kinase C and that protein kinase C activation is important for the stimulation of gene transcription. Finally, we show that GM-CSF binding stimulates c-jun protooncogene transcription and activates other genes which contain the AP-1 enhancer sequence. In this proposal, we will (1) examine the role of the secreted receptor in the biologic activity of this hormone (2) study how tyrosine kinases and protein kinase C interact to mediate the effects of GM-CSF on transcription (3) determine whether protein phosphorylation mediated by GM-CSF activates binding of Fos/Jun proteins to the AP-1 enhancer sequences. In addition we will map the c-jun enhancer to determine which sequences are necessary for the transcriptional activation of this gene by GM-CSF. The results of these studies will illucidate how the binding of GM-CSF to its receptor functions to mediate gene transcription. By understanding the early events stimulated by GM-CSF, we would hope to better understand how this agent stimulates growth and differentiation of hematopoietic cells. This knowledge will enable us to use this agent more effectively in the treatment of disease and to block its activity when it functions to promote the growth of neoplastic cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK044741-04
Application #
2144003
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1992-03-01
Project End
1996-02-29
Budget Start
1995-03-01
Budget End
1996-02-29
Support Year
4
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of Alabama Birmingham
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
004514360
City
Birmingham
State
AL
Country
United States
Zip Code
35294
Lilly, M B; Zemskova, M; Frankel, A E et al. (2001) Distinct domains of the human granulocyte-macrophage colony-stimulating factor receptor alpha subunit mediate activation of Jak/Stat signaling and differentiation. Blood 97:1662-70
Lilly, M; Sandholm, J; Cooper, J J et al. (1999) The PIM-1 serine kinase prolongs survival and inhibits apoptosis-related mitochondrial dysfunction in part through a bcl-2-dependent pathway. Oncogene 18:4022-31
Biggs, J R; Kraft, A S (1999) The role of the Smad3 protein in phorbol ester-induced promoter expression. J Biol Chem 274:36987-94
Matsuguchi, T; Lilly, M B; Kraft, A S (1998) Cytoplasmic domains of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor beta chain (hbetac) responsible for human GM-CSF-induced myeloid cell differentiation. J Biol Chem 273:19411-8
Matsuguchi, T; Kraft, A S (1998) Regulation of myeloid cell growth by distinct effectors of Ras. Oncogene 17:2701-9
Franklin, C C; Srikanth, S; Kraft, A S (1998) Conditional expression of mitogen-activated protein kinase phosphatase-1, MKP-1, is cytoprotective against UV-induced apoptosis. Proc Natl Acad Sci U S A 95:3014-9
Biggs, J R; Ahn, N G; Kraft, A S (1998) Activation of the mitogen-activated protein kinase pathway in U937 leukemic cells induces phosphorylation of the amino terminus of the TATA-binding protein. Cell Growth Differ 9:667-76
Matsuguchi, T; Zhao, Y; Lilly, M B et al. (1997) The cytoplasmic domain of granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor alpha subunit is essential for both GM-CSF-mediated growth and differentiation. J Biol Chem 272:17450-9
Zhao, Y; Loyer, P; Li, H et al. (1997) Cloning and chromosomal location of a novel member of the myotonic dystrophy family of protein kinases. J Biol Chem 272:10013-20
Sakai, I; Kraft, A S (1997) The kinase domain of Jak2 mediates induction of bcl-2 and delays cell death in hematopoietic cells. J Biol Chem 272:12350-8

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